Jan 10 (Reuters) - Ecuador is reeling from a fresh wave of violence that has shaken the South American nation, with President Daniel Noboa launching a military crackdown on gangs after criminal groups took more than 100 prison staff hostage and armed men dramatically interrupted a live television broadcast.

The crisis highlights the challenges ahead for Noboa, who took power in November after pledging during an election campaign to curb violence as drug trafficking gangs increasingly transport cocaine through Ecuador.